Bracelet link elements of this type are already known. The casing is generally made in a single piece, then it is secured to the strand.
In order to secure the casing to the strand, the front end of the strand is generally bent in order to form a loop into which the casing is introduced.
CH Patent No. 689,369 also proposes arranging the casing at the front end of the strand then covering the strand and the casing with a common envelope so that the casing is assembled with the strand. The envelope thus secures the casing to the strand.
All of these methods of securing the casing require detailed and expensive operations.